Last I checked, a Z80 was a dollar or two a chip. Why aren't we all running
massively parallel Z80 machines? Perhaps because building a machine with
500 CPUs will be much more expensive than buying them and writing software
to do anything useful on them will be a monumental task?

But what good will it do for me? I used to work with Transputers, which
were going to lead to these massively parallel computers built from cheap
CPUs. Didn't happen, because there were few areas where massively parallel
CPUs had benefits over a single monolithic CPU.

I find discussion of voxel rendering pretty bizarre from someone who
complains about my regarding 32MB as a 'reasonable amount' of memory for
a graphics chip. Reasonable voxel rendering is likely to need gigabytes
of RAM, not megabytes.